Fill in the blanks with an appropriate word from the table:
|
nostrils
|
chest
|
diaphragm
|
|
downwards
|
ribs
|
21%
|
|
air
|
16.4%
|
hair
|
|
skin
|
trachea
|
spiracles
|
|
gills
|
cutaneous
|
heart
|
1. The muscular sheet known asforms the floor of the chest cavity.
2. The air we exhale includes of oxygen and 4.4% of carbon dioxide.